Transmission fault

Hello, I need help.
The car is Chrysler town and country 2001 year 3.8 petrol 4 speed automatic gearbox.

I get fault codes p1775 p1784 p0700 all three at a time and the engine check light illuminated. After I erase the faults they appear later driving the car.
The strange thing is that's the transmission works great even with those faults. No limp mode or other noticable problems.

I checked the main connector to solenoid valve computer ,everything looks good. The fluid level in the transmission is ok.

I watched this video

and I think maybe some wires are bad? The relay works the same like in this video.

If there was a bad solenoid then the gearbox would not work well?
Sorry for my language mistakes
Looking for help

I did some digging and found the following. I'm not a transmission expert. Hopefully this info can point you in the right direction.

P0700 is a generic tcm fault sent to the ecm to light the MIL.

P1775 is a tcm solenoid fault.

P1784 is a tcm pressure sensor fault.

Harness information:

There is an 8 wire solenoid pack harness, located near the transmission dipstick tube. Pins 1-3 are pressure switch signals. Pin 4 is the relay output. Pins 5-8 are solenoid control.

Testing info:

All testing is done with the key off and the harness unplugged using an ohm meter. With one test lead connected to the relay output pin.

Pins 1-3 should be 270-330 ohms.

Pins 5-8 should be 1.5-1.8 ohms.

I' m frustrated here.
I've opened all the original cables under the isolation,everything looks fine, no corrosion or broken wires. Checked all the connectors relays fuses and everything looks good.

I have erased the faults drive the car for two days without faults and today those transmission faults appeared again. It is very strange because the gearbox works great. I'm using cheap Chinese elm 327 scanner maybe the faults are not like it is written?



Found only one thing that looks bad it is the transmission computer located near the front wheel under the mudguard. It is in very bad shape all the bolts are broken or churned. The computer body is broken on the corner. But the microchip is under the gel and the connector looks great. Is it possible this could be the problem? That the fault appears at any time.

Wow I wouldn't rule it out! And i think I'd probably start there if it's not the problem it sure has the potential to become the problem! Also the solenoid control pack located on the front of transmission is a possibility on a side note these Transmissions were prone to internal failure as well... does your elm give you your CVI?

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Hey Digileksik! I've been doing some reading about the codes you're getting - I think your scanner is telling you the truth, as far as the codes themselves.

P1775 is Switching Solenoid Stuck in TCC Position, and P1794 is Low/Reverse Clutch Pressure Switch Circuit. At first, they sound unrelated, but this transmission is weird. :silly: It uses the low/reverse solenoid for both 1st gear AND the torque converter clutch. As soon as the transmission shifts into second gear, a switching valve repurposes the low reverse solenoid for the torque converter clutch. Knowing that, it's easy to connect the dots between the codes you have.

That TCM definitely isn't looking good. :blink: But, given the intermittent nature of this problem, it makes me think there's an internal fault in the valve body causing this issue. That's where the switching valve lives, and it could easily be sticking one way or the other. What does the transmission fluid look like?

What is CVI Ben? I'm using my scanner just for reading and deleting faults

The transmission fluid level is OK and the fluid itself is new changed about 2000km ago.

Also I found this info.
"The P1775 code is set if three unsuccessful attempts are made to get into 1st gear in one given ignition start".

I haven't seen anything like that , driving in a parking lot everything looks fine ,driving fine backwards and forwards when changing gears.

Found a spare tcu computer in a chrysler scrap yard the seller agrees to let me test if this is a computer problem so maybe I will try that . I don't know what to do else. Next thing maybe change solenoid valve pack